Chevrolet’s Bolt, an all-electric car expected in showrooms as soon as 2017, will be able to travel 200 miles between charges and cost around $30,000 after government incentives, General Motors says. That’s bending the curve on what’s been a niche market.

Chevrolet’s Bolt, an all-electric car expected in showrooms as soon as 2017, will be able to travel 200 miles between charges and cost around $30,000 after government incentives, General Motors says. That’s bending the curve on what’s been a niche market. (Bill Pugliano, Getty Images)

The Toyota Prius is by far the bestselling hybrid in U.S. history, with more than 1.8 million units sold since its debut as a 2001 model. It has, in recent years, often been the bestselling car of any kind in California. Above, a Prius assembly line in Japan in December.

The Toyota Prius is by far the bestselling hybrid in U.S. history, with more than 1.8 million units sold since its debut as a 2001 model. It has, in recent years, often been the bestselling car of any kind in California. Above, a Prius assembly line in Japan in December. (Kazuhiro Nogi, AFP/Getty Images)

The next Toyota Prius will arrive just as hybrids seem to be going out of fashion.

Set to debut this fall, the 2016 version of the groundbreaking green car leads a segment beset by falling gas prices and rising efficiency of conventional gasoline cars.

The fourth-generation Prius, analysts say, will have to be an extraordinary car to match its previous successes, and it's unlikely to breathe new life...

Chevrolet’s Bolt, an all-electric car expected in showrooms as soon as 2017, will be able to travel 200 miles between charges and cost around $30,000 after government incentives, General Motors says. That’s bending the curve on what’s been a niche market.

Chevrolet’s Bolt, an all-electric car expected in showrooms as soon as 2017, will be able to travel 200 miles between charges and cost around $30,000 after government incentives, General Motors says. That’s bending the curve on what’s been a niche market. (Bill Pugliano, Getty Images)

Today the selection of efficient, lower-pollution cars includes a bewildering array of technologies and models — hybrids, plug-in hybrids, battery electrics, diesels and hydrogen fuel cells. Conventional gasoline cars, meanwhile, have made great strides in going farther on less fuel.

The Obama administration on Friday proposed tougher mileage standards for medium and heavy-duty trucks, the latest move by President Barack Obama in his second-term drive to reduce pollution blamed for global warming.

The Environmental Protection Agency issued new rules that would lower carbon dioxide emissions from trucks and vans by 24 percent by 2027. It would cut fuel costs by about $170 billion...